Most industrial and municipal processes require water treatment facilities to treat effluents returned to the environment. Such facilities typically represent a significant investment by the business/community, and the performance of the facility (or failure thereof) can seriously impact ongoing operations financially and in terms of operational continuity.
Moreover, not all effluent treatment requires the same technologies. Industrial effluents (such as is found at coal bed methane facilities or oil production sites, for example) all have different particulate, pollutant and/or biomass content inherent to both the industrial processes as well as the particular water and soil conditions found at the site. Municipal requirements would likewise vary depending on desired end-of-pipe quality and use (and again depending on the feed water present at the site).
The goal of all biological wastewater treatment systems is to remove the non-settling solids and the dissolved organic load from the wastewater by using microbial populations. The microorganisms used are responsible for the degradation of organic matter and the stabilization of organic wastes. Various effluent treating systems use aerobic microorganisms (i.e., microorganisms that require oxygen for their metabolism). These microorganisms use the organic content, including anaerobic iron accepting bacteria, of the wastewater as an energy source to grow.
One specific biological medium used consists of genetically altered aerobic microorganism cultures. The organic load of this treatment system is incorporated in part as biomass by the microbial populations, and almost all the remainder is liberated as gas. Unless the cell mass formed during the biological treatment is removed from the wastewater, the treatment is largely incomplete because the biomass itself will appear as organic load in the effluent and the only pollution reduction accomplished is that fraction liberated as gas.
Heretofore utilized biological contactor systems have included rotating biological contactors employing a biological film supported on a rotating plastic material disk or disks in a trough through which settled sewage flows. The disks are only partially submerged and, therefore, the biomass is subject to periodical removal from the wastewater flow (required since the oxygen needed for respiration is extracted from atmospheric air). Excess biomass is continually sloughed from the support disks and treated effluent must therefore be discharged into a secondary clarifier to settle entrained solids prior to further treatment.
Biological cleaning and recycling of aqueous based effluence from various mining, manufacturing and/or municipal facilities is handled in a variety of ways. For example, outflow from produced water from coalbed methane wells is directed to stationary, multi-chamber anaerobe denitrification septic tank systems for the reduction of the chemical oxygen demand. This approach requires a large commitment for permanent installation and construction. This approach is thus usually associated with substantial capital and fabricating costs as well as significant operating cost.
Heretofore known systems and methods for biological wastewater treatment are also often highly energy consumptive, noisy and/or smelly, space consuming and difficult to clean and/or maintain. Moreover, reliability and stability of such systems could be improved, as could their adaptability to automation. Surplus activated sludge generation should also be reduced. Therefore, improved biological treatment technologies could still be utilized.